Oracle Standard Edition costs about the same as Microsoft SQL Server. It can only be licensed on servers, or server clusters, that have a maximum capacity of 4 processor sockets.(revoked)

Oracle Standard Edition 2. It can only be licensed on servers, or server clusters, that have a maximum capacity of 2 processor sockets.

Oracle Standard Edition One is less expensive than SQL Server. It may only be licensed on servers that have a maximum capacity of 2 processor sockets. (revoked)

Oracle PE is very inexpensive, full-featured version of Oracle DB, but is restricted to one user per database (server, not instance, most likely). The license however allows a developer to use all of the features of the EE including the options (with the exception of Real Application Clusters).

Oracle Enterprise Manager (OEM) Database Control and Grid control is provided free of charge, however, the management packs needs to be licensed for the number of users or CPU's that you "monitor" with it.

Oracle Application Server (iAS) Standard Edition One may only be licensed on servers that have a maximum capacity of 2 processor cores.

A great comparison document showing what is included and what isn't for all of the editions of the Database is available at Oracle.com. See page 10 for the beginning of the comparison table.

A license is the "right to use" (RTU) the software and not the software itself. If you have a license, you can obtain a copy of the software media through whatever means - download , use the CDs from your last project, etc.

Please note that Oracle doesn't use software keys. You can just install the software and use it. It is up to you and your consciences to license the software before using it.

Licenses are not tied to the product version. For example, an Enterprise Edition database license is equally valid for Oracle 9i, Oracle 10g , Oracle 11g or latest Oracle 12c. However, you are only entitled to new versions if you have a valid maintenance and support contract in place.
For Oracle Standard Edition, be aware that versions 12.1.0.2 and newer do require Oracle Standard Edition 2 licensing.

Oracle licenses can be obtained by speaking directly with Oracle, through an Independent Software Vendor (ISV) (in the case of ESL or ASFU licenses), or through an Oracle Partner (i.e., Oracle License Store).

A Unlimited License Agreements (ULA) is a time-based (2-3 year) unlimited use right license for a subset of Oracle technology or applications. At the end of the term, customers must count and declare usage to Oracle, and are granted that number of licenses for the products covered by the ULA.

You pay per Processor you run the Oracle software on; however Oracle has a special definition of "processor" which may or may not match that of your hardware vendor.

Intel Hyperthreading technology that makes one core look like two counts as 1 cpu core for this purpose. Other soft partitioning technologies are treated differently; for example, the Solaris OS has a concept of Containers, this is similar to hard partitioning on an HP machine; however Oracle does not recognize software partitioning with Solaris Containers prior to Solaris 10; and even then there are stipulations. Hard partitioning methods such as Sun's Domains, IBM's Logical partitioning are recognized as legitimate methods to limit the amount of resources that can run the Oracle software. Also Oracle VM and certain Oracle Appliances configured as per Oracle's hard partitioning policy document is also allowed as a valid hard partitioning method.
If you are a MS or VMWare virtual machine user, the following document is a must read; Oracle Partitioning Policy document

If you use Standard Edition or Standard Edition One on a 2 processor system you simply need 2 processor licenses. Effective 1-Sept-2015, when licensing Standard Edition DB programs, a processor is counted equivalent to a socket; however, in the case of multi-chip modules, each chip in the multi-chip module is counted as one occupied socket. Oracle has now replaced Oracle Standard Edition and Oracle Standard Edition One with just Oracle Standard Edition 2 (SE2).

If you use Enterprise Edition you need to take the number of cores into account as well.

1.00 for Intel Itanium Series 93XX (For servers purchased on or after Dec 1st,2010)

1.00 for Intel Itanium Series 95XX

For example, a SUN UltraSparc T1 system with 4 x eight-core processors will require 4*8*0.25 = 8 licenses.
This is just an example. Sun UltraSparc T1 and T2 are not SMP capable, only Sun UltraSparc T2+ is SMP capable.
Similarly, an IBM AIX system with 4 x eight-core processors will require 4*8*0.75 = 24 licenses.

As at February 13 2006, Oracle still did not recognise "soft partitioning" technologies such as VMWare and Microsoft Virtual Server when licensing by processor/CPU. Instead you must licence by the physical processor in the underlying hardware. (see http://www.oracle.com/corporate/pricing/partitioning.pdf) "hardware partitioning" technologies are recognised, but Oracle places some caveats on this also.

Oct 1 2009 - Sparc T2+ Update Oracle Processor Core Factor Table has been revised with respect to Processor Licensing Factor for Sun UltraSPARC T2+ from 0.75 to 0.50. The rationale for change is that the benchmark for T2+ is more in line w/ Intel Xeon; hence the factor aligns with the factor for Intel Xeon on this table.

Pay per user, however user is defined as any end-node that receives data from or creates data for that Oracle DB including human users. The classic case would be a grocery store system that is taking data from refrigerator thermometers and point of sale systems; in one case a user is a thermometer and in another case the user is the check out clerk, or in the case of newer self-check out terminals it would be the customer; thus in this example one would explore processor based licensing. You are required to adhere to the following Oracle user minimums:

All other Oracle Application Server products: 10 Named User Plus licenses per CPU

Note: As can be deduced from the above, in the case of Standard Edition One and Standard Edition there doesn't appear to be anything that specifies whether the minimum of 5 is per customer, per server or per processor (and if per processor, whether the core factor is considered despite the fact it isn't for Standard processor licensing).

Concurrent Device (CD) licenses were defined as the 'Maximum amount of input devices connecting to the designated system at any given point in time'. There is a Network version of this license which has slightly different terms.

For Oracle Database Enterprise Edition, a minimum of 8 Concurrent Device licenses per Processor applied. This is a very old licensing metric and anyone using it on multi-core processors, or moving to such a license, should conduct a cost assessment.

This model is not available anymore. Although, some customers still maintain/renew their CD license agreements.

An Application Specific Full Use (ASFU) license is a restricted type of license sold by a Solution Provider / Application Vendor in conjunction with its third-party Application Package.

This license would then be application specific and cannot be used for anything else. Customer should renew the license every year in advance with Application Vendor for avail all the supports and compliance the ASFU license (or) can be migrated to Full Use (FU) license with additional cost and renew directly with Oracle or any other authorised Oracle partner.

For example, you can buy a ASFU license from SAP AG to use Oracle with the SAP/R3 system. This license would then be application specific and cannot be used for anything else, should be renewed with application vendor

An Embedded Software License (ESL)[1] is a very restrictive license type available from Independant Software Vendors (ISVs) who embed Oracle technology into their product. An end-user may not even be aware that the software package contains Oracle technology and should not be able to access it directly as a developer or system administrator.

An example of this licensing model in use may be a Point of Sale system that requires a database to log transactions.

Note that the standard Oracle License and Services Agreement only allows use of Oracle software for internal business operations. Other uses, such as a hosting service or an ASP, will require an agreement that extends the usage rights to cover such scenarios.

Oracle have a validation program which provides assurance that their LMS (License Management Services) team will accept data from certain third party vendor as being suitable for license review purposes.

Situations may arise where options in the Oracle technology or applications stack are being used that were not paid for, or where use may be extending beyond the scope of the contractual terms. Most of these cases occur due to lack of knowledge of the Oracle licensing scheme and a failure of managers to regularly audit license usage.

Some possible license compliance cases are:

More users than what are licensed.

More CPU's than what are licensed.

A less expensive edition of a product even though a server's size would necessitate high end licenses (SE1 vs. SE vs. EE).

Mixed support: licenses with active support and others where support has not been paid for.

Using options such as the Tuning and Diagnostics Packs that are part of GRID Control, which is free, but need a separate license. Same goes for Partitioning and RAC (except for in SE) it is an extra cost.

Customizing and modification of E-Business Suite components may necessitate full use Oracle Application Server and Database licenses.

Typically, when your Oracle rep. gains knowledge of such a situation a company could face an audit by Oracle. It is highly advisable to conduct a yearly audit of servers with a partner that understands Oracle licensing.

Early awareness of potential issues and vulnerabilities through Oracle Security Alerts

The renewal will enables to get support, patches from Oracle

Enable to upgrade the Oracle product to latest version without any additional cost.

Customers with unsupported programs are not entitled to download, receive, or apply updates, maintenance releases, patches, telephone assistance, or any other technical support services for unsupported programs.

Software patches and supportability enhancements

Proven best practices from Oracle and the global My Oracle Support Community

Risk:

If Oracle finds the partial license renewal in an environment during audit, LMS have the rights to take decision of stopping support for part of the Oracle licenses which was renewed.

Heavy penalty will be forced if any Oracle support used or patches applied on partial license renewed environment during audit

You may de-support a subset of licenses in a license set only if you agree to terminate that subset of licenses.

Re-pricing: In the event that a subset of licenses on an environment is not renewed or if the level of support is reduced, support for the remaining licenses on that license order will be priced at Oracle’s list price for support in effect at the time of termination / stop the renewal or reduction minus the applicable standard discount.

Refer the below line to understand more about Oracle Software Technical Support Policies

This section lists some scripts that can be executed to see (some of) the components that should be licensed:

Number of users and CPU/Processors:

select * from v$license;

Please note that the information provided by this command is not trustworthy on multi-threaded, multi-core or virtual systems. It is the number of processors understood to be available by the database - not the number of processors which must be licensed.

Please note - Option installation does not NECESSARILY equate to license requirement. Each licensable option has a number of tests required - see "Deployment Identification for License Review Purposes" section below for more details.

It should be noted that the scripts above are not definitive and are not accepted by Oracle LMS (License Management Services) team. Oracle has a validation program which provides assurance that their LMS team will accept data from certain third party vendors as being suitable for license review purposes.